#define _CRT_SECURE_NO_WARNINGS 1
class Sum {
public:
    Sum()
    {
        _ret += _i;
        _i++;
    }


    static int Getret()
    {
        return _ret;
    }
private:
    static int _ret;
    static int _i;


};


int Sum::_ret = 0;
int Sum::_i = 1;


class Solution {
public:
    int Sum_Solution(int n) {
        Sum a[n];
        return Sum::Getret();
    }
};
